The present invention relates to the oscillation of a bar code reader mirror for reflecting scanning light. In particular, the present invention relates to a dampening structure for dampening undesirable mirror oscillation.
Typically, bar code reader mirrors are supported by bearings for oscillation about a predetermined and fixed rotational axis. Oscillation of such a mirror is promoted by a spring arrangement. However, the use of bearings such as ball bearings to restrict oscillation about the rotational axis dampens the oscillation and consumes energy. Accordingly, attempts have been made to eliminate the bearings and provide spring configurations which promote oscillation about a desired axis. One problem which can occur with oscillator arrangements which are bearing free is the potential for undesirable mirror oscillations which occurs about axes other than the rotational axis. Undesirable mirror oscillations are frequently induced into such oscillator arrangements by forces external to the bar code readers (e.g. jarring of the bar code reader support.
Thus, it would be desirable to provide a structure which supports a mirror for oscillation about a predetermined rotational axis which is bearing free and not subject to oscillation about other axes.